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Munoz A.,Area de Desarrollo Acuicola | Munoz A.,Catolica del Norte University | Segovia E.,Arturo Prat University | Segovia E.,Catolica del Norte University | Flores H.,Catolica del Norte University
Latin American Journal of Aquatic Research | Year: 2012

In this study results related to reproductive conditioning, spawning and larval culture of Graus nigra ("vieja negra", "mulata") are given. Wild adult fishes were collected and used as brooders which at the end of the conditioning period reached gonadal maturation state and spawned naturally and spontaneously. Eggs were collected and after 36 hours of incubation they hatched at average rate of 60%. The hatched larvae measured 2.9 ± 0.23 mm and at day 50th post hatching (PE) reached a total length of 12.6 ± 0.37 mm. The larval survival after hatching was between 50.9-79.1%, and at day 30 PE it was 12.1%. Larval culture was developed in tanks supplied with filtered and sterilized seawater. After yolk sac reabsorption the digestive tract development occurs and larvae were fed with live foods enriched with highly unsaturated fatty acids emulsions. Then, at day 35th larvae were offered with artificial food with size progressively greater as ontogenetic development progressed. Anatomical evolution of larvae and morphometric relationships depicting its development is described. Larval growth pattern up to 50 days post-hatching is characterized. Aspects related to larval survival and the introduction of improvements optimizing larvae and juvenile production of this species are discussed.

Munoz A.,Area de Desarrollo Acuicola | Munoz A.,Catolica del Norte University | Segovia E.,Arturo Prat University | Segovia E.,Catolica del Norte University | And 3 more authors.
Latin American Journal of Aquatic Research | Year: 2015

Fish feeds are formulated with different ingredients, where fishmeal is the main source of protein. However, this input has a high cost, which leads to the need to evaluate new sources of protein and test them on marine species. Oplegnathus insignis (San Pedro, Pacific beakfish) is an omnivorous fish during its intertidal life stage switching to carnivore when it lives in subtidal habitats. This species has been reared experimentally, being necessary to incorporate formulated diets. To this end, this study reports the experiments in food and nutrition in juvenile O. insignis fed with formulated diets with different protein sources. The experiments were performed with hatchery-produced juvenile fish. Four foods, one based on fishmeal (reference) and three modified, replacing 30% of fish meal by other protein sources derived from soybean meal, mollusc meal and quinoa meal. We experimented with 180 ind. of 295.6 g and 450 days post-hatching, distributed in 12 rectangular tanks of 1.6 m 3. The feed was offered to satiety. Proximal analysis of experimental foods was performed in the feeds and faeces collected. Digestibility coefficients and total proteins were determined. The food with higher protein content was the flour containing molluscs meal. The higher total digestibility coefficient was determined in those foods made with fishmeal (68.0%) and molluscs meal (67.1%), while in those foods containing vegetable meals, total digestibility values were 62.7% for soybean meal and 64.1% for quinoa meal respectively. These results indicate that it is feasible to replace up to 30% fishmeal by vegetable flours. © 2015, Escuela de Ciencias del Mar. All rights reserved.

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